Conventionally, as disclosed in the Japanese patent publication 61-9128, there has been proposed an automatic operation control system. The control system contemplates reasonably executing such operations as a preparation of a mold for a molding operation, exchange of a material, a preparation of a molding machine and a setting of a molding amount and condition, because these operations are required to be executed in a short time and with a considerable efficiency owing to providing as peripheral devices a material feed device and a mold exchange device particularly in the injection molding machine to be used for producing a small amount of lots (a few to several tens lots) in a wide variety of products.
In the automatic operation control system comprising an injection molding machine, a material feed device and a mold exchange device, the molding machine and devices respectively have their exclusive controllers which are controlled as a whole by a main control unit, memory and input/output (I/O) device. The main control unit can read out through the I/O device the designated data relative to a molding preparation condition and a molding condition being entered into the memory and can transfer the data to the respective controllers which control operations of the injection molding machine, the material feed device and the mold exchange device according to such data.
The automatic molding system in the conventional injection molding machines is provided mainly to achieve a purpose of automation of a molding process in which products are molded. There is no proposal and implementation of automation of such operations as heating of a barrel, mold and hydraulic fluid, etc., a purge step before a molding operation, several stat-ups before beginning to produce completely molded products, an emergency stop under an abnormal condition an a restart following the stop. Almost all the operations are done manually except for only several operations including automatic energization of heaters by which a barrel and a mold is heated by using a calendar timer.
Therefore, conventionally, in this type of the injection molding machine, it is required to automate its start-up operation before beginning to produce the completely molded products and also required to immediately stop a molding operation when an emergency condition occurs during an automatic molding operation and return a proper start-up operation according to a timing of the stop upon restarting, so that a productivity of molding the products cannot be reduced.